An active directory setting restricts querying to only secure connections. Which of the following
ports should be selected to establish a successful connection?

A.
389

B.
440

C.
636

D.
3286

Explanation:
Port 636 is used for secure LDAP (LDAPS).
Incorrect Options:
A: Port 389 is used for LDAP.
B: Port 440 is not used for secure Active Directory connections.
D: Port 3286 is not used for secure Active Directory connections.

Dulaney, Emmett and Chuck Eastton, CompTIA Security+ Study Guide, 6th Edition, Sybex,
Indianapolis, 2014, p. 147
https://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers